He rehearses two points familiar to readers here. First, that almost all Labour’s policy announcements in the past year (it’s not a long list) are in tune with existing Lib Dem policy: reducing taxes for the low-paid, a mansion tax and ending wealthy pensioners’ benefits are just three of the ideas that started with the Lib Dems and have now been picked up by Labour:

It has also struck people on both sides that there is an increasing number of policy areas where Labour and the Lib Dems are converging. Ed Balls has adopted the Lib Dem mansion tax, partly to drive a wedge between them and the Tories and partly because he just likes the idea. The two parties are broadly in the same place on green energy, more housebuilding, the minimum wage, boosting capital spending on infrastructure and industrial strategy. They are getting within touching distance on other issues such as childcare. Labour’s plan to require teachers to have a regular “MoT” to check on their skills parallels Nick Clegg’s recent emphasis on teacher qualifications.

Both parties have strongly suggested that they would ask richer pensioners to surrender some perks, such as the winter fuel payment, which was, ironically, introduced by the mentor of the two Eds, one Mr Brown. They could almost certainly compromise about the top rate of tax. There is a division between them about how best to help the lower-paid. The Lib Dems want to increase further the personal allowance; Labour says it would restore the 10p band. That is a divide, but hardly an unbridgeable one. In the current coalition, constitutional reform has been a miserable disappointment for the Lib Dems: they have secured none of the big changes that they hoped for. While Labour would be highly reluctant to endorse changing the electoral system for the Commons after its rejection in the 2011 referendum, Ed Miliband and Nick Clegg ought to be able to find an agreement on Lords reform and possibly proportional representation for local government elections. The wording of whatever they say in their respective manifestos will be very important.

Andrew Rawnsley then goes on to make a related point, one I explored in October – that Labour could be tricky coalition partners for the Lib Dems precisely because there is broad agreement on a range of policy issues. ‘However much we raised the fairness stakes, you can bet Labour would out-bid us. Though perhaps they’d make some concessions on civil liberties to ensure they can blame us for any terrorist outrages,’ I noted. Here’s Rawnsley with a different-but-related point…

There is so much convergence, in fact, that the Lib Dems’ problem with going into government with Labour might be not be the number of disagreements, but the absence of them. There is now something close to a consensus view among leading Lib Dems that they should have done more to differentiate themselves from the Conservatives in the early phase of the coalition’s life. They believe lack of differentiation cost them their identity and with it many supporters. Hence the strategy they are pursuing now of being increasingly aggressive about asserting their divisions with the Tories. Maintaining a distinctive personality for the Lib Dems could actually be harder in coalition with Labour because they agree on too much.

But you know the old saying: the closer they are, the louder they shout. The only significant additional support Labour has picked up since 2010 has been from former Lib Dem voters (there has been remarkably little direct Labour-Tory switching) so the two Eds will be wary about being seen to be too friendly – at least this side of 7th May 2015.